Title : new
Usage : $dblink = Bio::Annotation::DBLink->new(-database =>"GenBank",
-primary_id => "M123456");
Function: Creates a new instance of this class.
Example :
Returns : A new instance of Bio::Annotation::DBLink.
Args : Named parameters. At present, the following parameters are
recognized.
-database the name of the database referenced by the xref
-primary_id the primary (main) id of the referenced entry
(usually this will be an accession number)
-optional_id a secondary ID under which the referenced entry
is known in the same database
-comment comment text for the dbxref
-tagname the name of the tag under which to add this
instance to an annotation bundle (usually 'dblink')
-type the type of information in the referenced entry
(e.g. protein, mRNA, structure)
-namespace synonymous with -database (also overrides)
-version version of the referenced entry
-authority attribute of the Bio::IdentifiableI interface
-url attribute of the Bio::IdentifiableI interface

Title : display_text
Usage : my $str = $ann->display_text();
Function: returns a string. Unlike as_text(), this method returns a string
formatted as would be expected for te specific implementation.
One can pass a callback as an argument which allows custom text
generation; the callback is passed the current instance and any text
returned
Example :
Returns : a string
Args : [optional] callback

Title : tagname
Usage : $obj->tagname($newval)
Function: Get/set the tagname for this annotation value.
Setting this is optional. If set, it obviates the need to
provide a tag to Bio::AnnotationCollectionI when adding
this object. When obtaining an AnnotationI object from the
collection, the collection will set the value to the tag
under which it was stored unless the object has a tag
stored already.
Example :
Returns : value of tagname (a scalar)
Args : new value (a scalar, optional)

Title : primary_id
Usage : $self->primary_id($newval)
Function: set/get on the primary id (a string)
The primary id is the main identifier used for this object in
the database. Good examples would be accession numbers. The id
is meant to be the main, stable identifier for this object
Example :
Returns : value of primary_id
Args : newvalue (optional)

Title : optional_id
Usage : $self->optional_id($newval)
Function: get/set for the optional_id (a string)
optional id is a slot for people to use as they wish. The
main issue is that some databases do not have a clean
single string identifier scheme. It is hoped that the
primary_id can behave like a reasonably sane "single string
identifier" of objects, and people can use/abuse optional
ids to their heart's content to provide precise mappings.
Example :
Returns : value of optional_id
Args : newvalue (optional)

Title : object_id
Usage : $string = $obj->object_id()
Function: a string which represents the stable primary identifier
in this namespace of this object. For DNA sequences this
is its accession_number, similarly for protein sequences
This is aliased to primary_id().
Returns : A scalar

Title : version
Usage : $version = $obj->version()
Function: a number which differentiates between versions of
the same object. Higher numbers are considered to be
later and more relevant, but a single object described
the same identifier should represent the same concept
Returns : A number

Title : authority
Usage : $authority = $obj->authority()
Function: a string which represents the organisation which
granted the namespace, written as the DNS name for
organisation (eg, wormbase.org)
Returns : A scalar

Title : namespace
Usage : $string = $obj->namespace()
Function: A string representing the name space this identifier
is valid in, often the database name or the name
describing the collection
For DBLink this is the same as database().
Returns : A scalar